Cerebellar restricted diffusion in Wernicke's encephalopathy.

Area of Science:

• Neurology
• Internal Medicine
• Radiology

Background:

• A 50-year-old woman with a history of uterine cancer and chronic radiation enteritis presented with acute lower limb pain, later diagnosed with aortoiliac stenosis.
• Following stent placement, she developed altered mental status, ataxia, and ophthalmoplegia, rapidly progressing to a stuporous state.

Purpose of the Study:

• To report a complex case of Wernicke's encephalopathy presenting atypically in a patient with risk factors including poor oral intake and prior chemoradiation.
• To correlate clinical presentation with neuroimaging findings suggestive of thiamine deficiency.
• To emphasize the importance of considering Wernicke's encephalopathy despite potentially normal or falsely elevated thiamine levels.

Main Methods:

• Clinical case presentation with detailed neurological examination and patient history.
• Neuroimaging including Magnetic Resonance Imaging (MRI) of the brain, focusing on diffusion-weighted imaging (DWI) and T2-FLAIR sequences.
• Biochemical testing of serum thiamine levels and consideration of factors affecting assay results (enteral feeds).
• Therapeutic intervention with high-dose intravenous thiamine replacement.

Main Results:

• MRI revealed restricted diffusion and T2-FLAIR hyperintensities in the cerebellum, dorsomedial thalami, and fornix, with mammillary body enhancement, consistent with Wernicke's encephalopathy.
• Serum thiamine level was borderline (70 nmol/l), potentially falsely elevated due to enteral feeding.
• Following thiamine treatment, repeat MRI showed resolution of acute changes with mild cerebellar atrophy, and the patient exhibited subtle neurological improvement.

Conclusions:

• Wernicke's encephalopathy can present with diverse neurological deficits and imaging findings, sometimes masked by other medical conditions or laboratory results.
• Early recognition and aggressive thiamine repletion are crucial for improving outcomes in patients with suspected Wernicke's encephalopathy, even with non-specific or borderline thiamine levels.
• This case underscores the importance of a high index of suspicion for thiamine deficiency in patients with altered mental status and neurological deficits, particularly those with risk factors such as malnutrition or gastrointestinal issues.